Control system for billet marking



July 28, 1953 Filed April 1, 1947 H. E. MULLER, SR

CONTROL SYSTEM FOR BILLET MARKING 3 Sheets-Sheet l 3nnentor Her/77 an E.mu/e- .5/1

Hxs Gttorneg July 28, 1953 H. MULLER, SR 2,646,746

CONTROL SYSTEM FOR BILLET MARKING Filed April 1, 1947 3 Sheets-Sheet 2fig. 2.

3nnentor fie/777 m E. Mid/er 5/:

July 28, 1953 H. E. MULLER, SR

6 I CONTROL SYSTEM FOR BILLET MARKING Filed April 1, 1947 fig. 4.

3 She ecs-Sheet 3 Z'mnentor Herman E. Mu//e/' Jr. 8

H la altorneg Patented July 28, 1953 Herman E. Mullen-Sr Swissvaley-Pag'assignor 1 to United States Steel Corporation, .a. corpora-' tion of NewJersey Application April 1', 1947,Serial Manama .zoiaimsl (o1. 101-4).

I "This invention relates to control systems, and more particularly tocontrol systems for apparams for performing a predetermined'operation ona'fwork object which is moved along a conveyor, although not limitedthereto;

Accordin to anillustrative embodiment, the apparatus ofjthe presentinvention may be utilized in combination with a billetstampingapparatus, the same being illustrated in the drawings anddescribed more fully hereinafter.

,In some steelmills. it is the practice to stamp the end of heavy metalbillets with the number of the; heat of steel from which they were made.Ordinarily the stamping of the end of the billet isjaccomplished as it'rnoves along a conveyor. In the past this has been accomplished by anoperationilwhich is either manual, or manually initiated; In some casesit has been found expedient to; move the billets endwise along aconveyor and tomount over the conveyor a pivoted arm on which the heatnumbers are detachably mounted, thejsa'i'd iarm'being actuated by anadjacently disposedfluid cylinder through the medium of a controlswitch, itself susceptible to manual operation. "Morerecently themanually operated switch has been superseded by photoelectric controls.It hasheretofore been proposed to so mount photoelectric orlight-sensitive cells, and their Iightsourceathat the advancing end ofthe billet will interrupt the light, to the first cell, but the solenoidwill notbe actuated until the advancing end of the, billet interruptsthe light to the second celL-at which time the trailing end of thebillet islimmediately below the operative point, of the swinging armcarrying the billet stamp ;f and it is at, thisjpoint thatthe fluidcylinder is actuated t'oswing the arm in its lowermost position andthereby move. the said billet stamp against the trailing end of theingot with the, requisite force.

, While no difiiculty or danger is to be experienced were the light raysto the first of these photoelectric cells accidentally interrupted, ithas been found that the accidental interruption of light rays to thesecond photoelectric cell while any portion of the advancing billet isinterrupting the light rays ,to the first cell will result in theaccidental and possibly dangerous downward movement of the heavyswinging arm with its heavy billet stamp. It is accordingly among theobjects of the present invention to provide a control system which maybe used in various operations such as the motivation of the billetstampin apparatus referred to, and by means of which the desired controlof the apparatus is insured against improvident or accidental operation.

through a downward arc 2 Another object is the-attainment of theforegoing by the use of instrumentalities which are simple and inexpensiveto manufacture and install, and ones which are at the same time quitedurable in service. h a.

The invention, then, comprises the features hereinafter described and'asparticularly pointed out in the claims, the following description-andthe annexed drawings setting forth in detail certain illustrativeembodiments ofthe invention,

these being indicative of several of the number of ways in which theprinciples of the invention may be employed.

In said drawingsz. Figure 1 is a side elevation of a conventionalinclined conveyor of the'type adapted to'endwise or longitudinally movea succession of heavy steel billets, the said conveyor being providedwith a superposed billet stamping apparatus;

Figure 2 is a plan of the showing of Figure 1 but on a reduced scale,and showing in addition certain photoelectric cells and light sourceswhich will be described more fully hereinafter;

Figure 3 is a simple and conventionalelectric circuit which may beutilized to operate the instrumentalities of the control system of thepresent invention; 7 v

Figure 4 is a fragmentary enlarged elevation of a modified solenoidsystem; and

Figure 5 is a simplified electric circuit which may be utilized tooperate the instrumentalities embodying the modified solenoid system ofFigure 4.

.Referring more particularly to the drawings. the. numeral 2 generallydesignates an inclined conveyor comprising a plurality of suitablydriven conveyor rolls which are, constructed and arranged tosuccessively feed elongate metal billets, or other workpieces, in,endwise fashion.

' Asshown most clearly in Figures 1 and 2, a frame 3 is mounted. atopthe inclined conveyor and carries-an elevated and transverselyexte'n'ding rotatable shaft 4.. Secured to this rotatable shaft 4 is oneend ofan arm 5, the other of, which carries a heavy'marking head 6; Suitablenume bers, or other marking media 1, aredetachably carried -by the head6, the samebeing soconstructed andarranged as to permit of, marking oneend of a metallic billet when the pivotally mounted .arm 5 is movedwith-sufficient force The frame};carriegadoubh-acting air cylinder I0,the outerand*inner ends of which com municatewith-aim-conduits n and I2,respectively. yflhese airconduits ll and- :l2 connect througha valvel3.with an air supply pipe I4. An

operating lever I5 is operable to alternately connect the air conduits ll and I2 with the air supply pipe l4 and an air exhaust pipe H.

The piston of the double-acting air cylinder is provided with the usualpiston rod 20, and to the latter there is pivotally connected anelongate rod 2| which extends over the arm 5. The extended end of theelongate rod 2| is pivotally C0111 nected to one end of a link 22, theother end of the said link being secured to the rotatable shaft 4.

Referring to Figures 2 and 3 of the drawings, as the elongate metalbillets are. movedalong the inclined conveyor 2 and pass under the frame3:, they travel through a field across which there is focussed a seriesof three substantially spaced photoelectric or other light-sensitiveunits, as shown at 50, 5| and 52. The distance between the. first andthird of these light-sensitive units is approximately the same as thelength of the metal billets (or other workpieces) which are to be markedby the marking media I carried by the marking head ii on the outer endof the pivotally mounted arm 5, the reason for which will appear short yhere af r- Each of the light-sensitive units 50, 5! and 52 is, actuatedby a light source, as at 53, 54 and 55, respective which s p ioimmediately o PDSite, on the other side of the conveyor and at r suchpoints as will enable the light rays emanating thereirorn to beintercepted by the metal billets during their forward movement along theinclined conveyor 2.

their own circuitthe light-sensitive units 50, 5t and re connected inparallel, whereas the ccntacto s of the relays they operate areconnected in serie and operate -a solenoid unit 65, which comprises aspring-loaded single-acting cylinder. Referring back to Figure 1, thissolenoid unit 65 actuatesthe operating lever l5 of the control valve I3.That is,'when the solenoid 65 is energizedit will swing the lever 15 ofthe control valve lei in the direction opposite to that shown in Figure1, with the result that the piston (not shown); within the air cylinderIt is caused to move to the right, causing the piston rod 20 and itspivotally connected elongate rod 2i to move in the same direction, withthe end result that the pivotally mounted arm 5 and its marking head iiiare. caused to swing downwardly. In this manner, then, the numbers orother marking media T are caused to make contact with the trailing endof a metal billet which is advancing along theinclined conveyor 2 andthrough a suitable guide, such as the conventional bell illustrated inFigure 1. When the solenoid unit 65 is deenergized the spring within itssingle-acting cylinder causes the lever IE or the control valve to eturn9.. t n tia po iti n. as iuF s r fhus th wqrk h cycle f. he contr l ve.315 suppl a, matt r of lte nat ly s-ener izin or ener izin h qidfln whthis eri nsd hr h en i o os he c n a t r .13. h nlay the i ht-sensi iv nt .0..

' S s h m nner. Opening or cl s n he 91 tacts of the relays of thehereinbefore described light-sensitive units 59;, 5l and 52; thesaidunits are, like their respectivelight-sources 53;;5ilfand 55-, connectedin parallel, whereasthe contactors of the photoelectric relays whichthesaidcontrol- (and which in turn control the solenoid unit 65) are inseries. 'W-ith the main switch Gill n closed position and the operatingarmo f;- the switch 62 in its downward or automatic posrtion, thecurrent flows to all ofthe photoelectric units directly, except to thesolenoid unit 65, for the reason that the contactors of the relays ofthe light-sensitive units 5| and 52 are normally open, while thecontactors of the relay of the light-sensitive unit are normally closed,all as hown in Figure 3.

If any interruption or the light rays emanating from the light sources53., 54 and 55 causes a reaction on the contactors of the relays of thelightsensitive units, it will have no effect on the soler gid unit 65.if one or the contactors is still open" because they are all connectedin series.

As the. metal billet moves along the inclined conveyor 2, its. leadingend interrupts the light rays emanating from the light source 53,thereby opening the. conta-ctors of the relay of the lightsensitive unit50. In progressing forwardly the billet, then interrupts the light raysemanating from the light source 54', with the result that thecontact-ors of the relay of the light-sensitive unit 5! are closed. Inprogressing further along the inclined conveyor 2' the leading end ofthe billet intercepts the light ray emanati g iromthe, light source 55,thereby closing the contactors of the relay of the light-sensitive orphotoelectric unit 52. Up until now the operating circuits oi thephotoelectric unit 5| and the photoelectric. uni 52 are closed, but theoperating circuit for the photoelectric unit 55 is open. Accordinglythere is no. energization oi the solenoid unit. 55, and this is for thereason that the billet is not as yet in position to be marked. However,in a very short interval of time the trailing endof the billet passesfrom between the light source 53. and the photoelectric unit 59 with theresult that the circuit of the latter (which was up. until now open.) isclosed. The solenoid 6.5. i energized. Withthe result that the, arm 5.is swung downwardly in the manner hereinbefore described, thus causingthe trailing end of the billet to be marked by the numbers or otherindicating media 1, carried in the marking head 6. The movement of thelever I5 of the control valve l3 in the opposite direction to thatillustrated in Figure 1 causes the said valve to permit compressed airto enter the air cylinder lflthrough the air conduit I2. The pive otallymounted arm 5 remains in a down position until the trailing end of thebilletpassesthe light rays emanating from the light sources5, 4f and,55, at which time there is broken the circuitsoi the photoelectric units5l and 52, thus deenergizing the. solenoid 6 5 and permitting the springwithin the spring-loaded single-acting air cylinder I ll to operatethevalve [3 to reverse the flow of air and permit same to flow through the.air conduit LI, thusreturning the arm 5 to its inoperative position.

According to the teachings of the present invention the. photoelectricunit 52 and its light source 55 constitute a safety measure as itprohibits the operation of the pivotally mountedarm 5 unless thecircuits of both the photoelectric units 5,1 and 52 are simultaneouslybroken, as is the case when a billet passes. The purpose of this is toprevent accidental operation Qf. the pivotally mounted arm 5 due to adropped tool or passing hand of the operator which might break the lightbeam.

Referring to Figures 4 and 5 of the drawings, there is illustrated amodified form of the invention which contemplates the use of two opposedsolenoids 66 and 6'! in lieu of the single solenoid of- Figures lthrough 3. According to this permissive embodiment one of the solenoids(i. e.

.5 erative position. This modification may be practiced by simplydisposing the solenoids '66 and 61 in the opposed positions shown inFigure 4 with their thrustor shafts in alignment and connected togetherthrough a link M which is provided with a pivotal connection 69 forreceiving the outer end of the operating lever I5 of the control valve[3.

If desired, suitable manual controls may be added and operated aftermoving the arm of the selector switch 62 into a vertical position withrespect to the showings of Figures 3 and 5.

While I have shown and described certain specific embodiments of thepresent invention, it will be readily understood by those skilled in theart that I do not wish to be limited exactly thereto, since variousmodifications may be made without departing from the scope of theinvention as defined in the appended claims.

I claim:

1. In combination with a conveyor and apparatus for marking the rearwardends of a series of billets being successively fed along the conveyor,said apparatus having a marking device in an initial operating positionout of the path of travel of the billets, means for actuating themarking device to mark a billet and means for resetting the markingdevic to initial position; a series of three light sensitive elementspositioned along the conveyor, a light source positioned opposite eachof said elements and directed across the conveyor toward its associatedelement at a height adapted to energize the same when a billet is notinterposed therebetween, said elements being spaced along the path oftravel of billets on the conveyor, the spacing between the first andlast of the elements being equal approximately to the length of abillet, whereby each of said elements are deenergized in sequence by thelead end of a billet passing along the conveyor and are reenergized inthe same sequence by the passing of the trailing end of the billet, asolenoid mechanically connected to the means for actuating the markingdevice and controlling the operation thereof, a first relay operable bythe first of said series of light sensitive elements along the path oftravel of the billets and having a pair of normally closed contactsopened by deenergization of said first element, a second relay operableby the second of said light sensitive elements and having a pair ofnormally open contacts closed by deenergization of said second elementand a third relay operable by the third of said light sensitive elementsand having a set of normally open contacts closed by deenergization ofsaid third element, said solenoid and aforementioned contacts of saidfirst, second and third relays being connected in series circuit to asuitable power source whereby the circuit to said solenoid is completedand the marking device is actuated only when the second and third lightsensitive elements are in the deenergized state and the first lightsensitive element is energized.

2. The combination of claim 1 which includes a solenoidmechanicallyconnected to the means for resetting the marking device toinitial position and controlling the operation thereof, a first relayoperable by the first of said series of light sensitive elements alongthe path of travel of the billets and having a pair of normally closedcontacts opened by deenergization of said first element, a second relayoperable by the second of said light sensitive elements and having apair of normally closed contacts opened by deenergization of said secondelement and a third relay operable by the third of said light sensitiveelements and having a pair of normally open contacts closed bydeenergization of said third element, said solenoid and aforementionedcontacts of said first, second and third relays being connected inseries circuit to a suitable power source whereby the circuit to thesolenoid is completed and the resetting means of the apparatus operatedonly when the third light sensitive element is deenergized and the firstand second light sensitive elements are energized.

HERMAN E. MULLER, SR.

References Cited in the file of 'this patent UNITED STATES PATENTSNumber Name Date 1,995,881 Cockrell et al Mar. 26, 1935 2,099,230 RixNov. 16, 1937 2,171,362 Gulliksen Aug. 29, 1939 2,339,204 Stockbarger eta1. Jan. 11, 1944 2,348,566 Papzian May 9, 1944 2,400,489 Dana et al May21, 1946

